PROBLEM: CD Player Digital Output
EADGBE
I have a Yamaha CX-1000 preamp and I just acquired a used Yamaha CD
player that has a digital output (CDX-710).
The CX-1000 preamp has digital inputs on it. Even though this CD
player sounds fine through the analog outputs, I wanted to hear what
the digital output sounded like.
I used a Monster Cable Datalink SP/DIF cable I had lying around to
connect the two.
PROBLEM: I get perfect audio through the left channel, but nothing at
all in the right channel. Needless to say, the CD player sounds great
in BOTH left & right channels when I use its analog outputs.
What could the problem be? I am unfamiliar with making digital
connections. Could I be using the wrong kind of cable? If there is a
breakdown somewhere, what would be the most likely problem?
I was always under the impression that digital, by definition, either
works or it doesn't. But I have a situation where "half" of it works
and the other "half" doesn't.
The problem doesn't really bother me, since I am satisfied with using
analog connections. But I am a bit puzzled about why I can't get both
channels working when I try to use a digital connection.
Thanks in advance for any assistance......
Adrian C
> PROBLEM: I get perfect audio through the left channel, but nothing at
> all in the right channel. Needless to say, the CD player sounds great
> in BOTH left & right channels when I use its analog outputs.
>
> What could the problem be?
Fault in the preamp, I'd wager. Do you have anything else with a digital
output you could try?
--
Adrian C
Gareth Magennis
"EADGBE" <hwbos...@comcast.net> wrote in message
news:fae88ad4-007a-4d8e...@l64g2000hse.googlegroups.com...
>
> I have a Yamaha CX-1000 preamp and I just acquired a used Yamaha CD
> player that has a digital output (CDX-710).
>
> The CX-1000 preamp has digital inputs on it. Even though this CD
> player sounds fine through the analog outputs, I wanted to hear what
> the digital output sounded like.
>
> I used a Monster Cable Datalink SP/DIF cable I had lying around to
> connect the two.
>
> PROBLEM: I get perfect audio through the left channel, but nothing at
> all in the right channel. Needless to say, the CD player sounds great
> in BOTH left & right channels when I use its analog outputs.
>
> What could the problem be? I am unfamiliar with making digital
> connections. Could I be using the wrong kind of cable? If there is a
> breakdown somewhere, what would be the most likely problem?
>
> I was always under the impression that digital, by definition, either
> works or it doesn't. But I have a situation where "half" of it works
> and the other "half" doesn't.
You cannot lose "half " of a serial data stream. The problem must be in the
preamp, somewhere between (and including) the D/A converter, and where its
output joins the analogue circuitry.
Gareth.
Arfa Daily
"Adrian C" <em...@here.invalid> wrote in message
news:6dmru5F...@mid.individual.net...
Agreed that you need to try something else as an input. Problem could be at
either end in that both channels may not be making it into one data stream
at the CD (unlikely) or (more likely) that the Yammy is either failing to
decode the missing channel, or failing to switch it. Do you have only a
coaxial digital connection ? Is there an optical one that you could try ?
Either coaxial or optical, you are correct in your assumption that it should
all "just work" as soon as you make that one connection.
Arfa
EADGBE
This particular CD only has the coaxial output -- there is no optical
output, although there are optical inputs on the preamp.
I have an Audio Alchemy CD player that also has a coaxial output, but
that player is not working at the moment.
One other though occurred to me: I should try the CD player into some
of the other digital inputs, just to see if maybe the CD input alone
is at fault (not likely, I know).
geoff
> I have a Yamaha CX-1000 preamp and I just acquired a used Yamaha CD
> player that has a digital output (CDX-710).
>
> The CX-1000 preamp has digital inputs on it. Even though this CD
> player sounds fine through the analog outputs, I wanted to hear what
> the digital output sounded like.
>
> I used a Monster Cable Datalink SP/DIF cable I had lying around to
> connect the two.
>
> PROBLEM: I get perfect audio through the left channel, but nothing at
> all in the right channel. Needless to say, the CD player sounds great
> in BOTH left & right channels when I use its analog outputs.
>
> What could the problem be?
The problem is a fault in the sending device, or the receiving device.
geoff
Kendra Weissbein
"geoff" <ge...@nospam-paf.co.nz> wrote in message
news:9oOdnZ9aYIXwEOvV...@giganews.com...
So which is it holmes? The Sending Device of the Receiving Device?
Mike S
> The problem is a fault in the sending device, or the receiving device.
>
>
> geoff
>
(obviously)
Gareth Magennis
"Mike S" <nospam> wrote in message news:4878627d$0$11601$607e...@cv.net...
Could someone please explain how it could be possible to lose one channel of
the digital stream out of the CD player, considering that the CD's audio
output is perfectly OK.
Gareth.
Don Pearce
Depends on the internal architecture, but I have to agree it is highly
unlikely.
d
Gareth Magennis
"Don Pearce" <nos...@nospam.com> wrote in message
news:X8udnTsGxvX98OXV...@posted.plusnet...
I would say close to Zero. I'll bet nobody here can cite a case where this
has actually happened.
Gareth.
Arfa Daily
"Gareth Magennis" <gareth....@ntlworld.com> wrote in message
news:3h_dk.25396$E41....@text.news.virginmedia.com...
It is very unlikely, I agree, but then in these days of extremely complex
internal architecture of most LSIs, there isn't much in the way of 'stock
faults' any more, and strange ones happen every few weeks in my experience.
That being the case, none of us could cite a case of a peculiar fault, until
it actually happened :-)
Unlikely or not, there is the remote possibility that this could be the one
for that fault ... I don't know if the PCM data stream coming off the disc
is decoded and processed first, or whether it is directly transcoded into
SPdif (or indeed, whether SPdif is just PCM under another name - I've never
bothered to check because it's very rare to get *any* fault in this area).
If there is any decoding going on, then just maybe, a channel *could* be
lost. But yes, in practical terms, almost certainly a problem in the amp.
Arfa
William Sommerwerck
Why are you arguing about such an unlikely event when the OP hasn't tested
the unit with another digital source?
Don Pearce
Far too sensible an idea. How can we argue the sound of one hand
clapping when someone says "try it and listen"?
d
Eeyore
EADGBE wrote:
> I used a Monster Cable Datalink SP/DIF cable I had lying around to
> connect the two.
>
> PROBLEM: I get perfect audio through the left channel, but nothing at
> all in the right channel. Needless to say, the CD player sounds great
> in BOTH left & right channels when I use its analog outputs.
Obviously you should have used a Monster STEREO cable instead of the cheap
model you bought.
Graham
Eeyore
Mike S wrote:
> At least he knows it's not the cable (obviously)
Don't tell the audiophools that ! Their entire religion will be destroyed.
Graham
Eeyore
Gareth Magennis wrote:
> "Mike S" <nospam> wrote
> >
> >> The problem is a fault in the sending device, or the receiving device.
> >>
> > That narrows down the possibilities! At least he knows it's not the cable
> > (obviously)
>
> Could someone please explain how it could be possible to lose one channel of
> the digital stream out of the CD player, considering that the CD's audio
> output is perfectly OK.
Failure to sync to the second block of audio data ? Bad clocks ?
Graham
Eeyore
EADGBE wrote:
> I used a Monster Cable Datalink SP/DIF cable I had lying around to
> connect the two.
Try using a cheap one.
Graham
Eeyore
Arfa Daily wrote:
> or indeed, whether SPdif is just PCM
You mean I2S.
> under another name
It is. Both are linear PCM. Simply mildly different data stream formatting.
Graham
Mike S
Yes. In the digital output the left and right channels are combined into
one digital stream, then sent over the coax cable to the receiver/preamp
where they arer separated into the two analog channels.
The problem here is in one of those stages. Either one of the channels is
being lost before it is encoded into that digital stream to be sent out of
the CD player, or a perfect digital stream is being sent to the preamp and
sometime after it is decoded into the two seperate channels, one channel is
lost due to a faulty component or a bad solder joint, loose connection, etc.
EADGBE
be the problem.
Is it actually possible that a cheaper cable could solve the problem?
And here is a question that will really show my level of ignorance
when it comes to digital audio formats: Is it possible that I am using
the wrong kind of digital cable? The digital output of the CD player
and the digital input on the preamp are both RCA type jacks. I simply
thought that using a digital coaxial cable with RCA plugs on both ends
would be appropriate. Am I wrong? Is there another type of cable I
should use that will fit?
Richard Crowley
>I have received a couple of comments here that my cable choice could
> be the problem.
>
> Is it actually possible that a cheaper cable could solve the problem?
NO they are joking. Since the same cable carries both the left and
right channels it is impossible that a passive device such as a cable
could reliably distingusih between the left channel data and the right
channel data in the stream.
> And here is a question that will really show my level of ignorance
> when it comes to digital audio formats: Is it possible that I am using
> the wrong kind of digital cable?
NO. It either works or it doesn't. It is as simple as that. People
might argue that if you use really poor cable it might introduce such
digital artifacts as "jitter". But there is no amount of arm-waving
that can explain how it could affect only one channel of the
interleaved data.
> The digital output of the CD player
> and the digital input on the preamp are both RCA type jacks. I simply
> thought that using a digital coaxial cable with RCA plugs on both ends
> would be appropriate. Am I wrong? Is there another type of cable I
> should use that will fit?
It is NOT the cable. Ignore the frivolity and go back to doing a proper
differential diagnosis with the source and destination equipment.
Richard Crowley
Note further that SPDIF has been demonstrated to work properly
using a wet string (literally). There is NOTHING magic about the
cable. Despite what Monster and the other rip-off cable shysters
may try to say otherwise.
Adrian C
> I have received a couple of comments here that my cable choice could
> be the problem.
>
> Is it actually possible that a cheaper cable could solve the problem?
Nope. Absolutely not.
Have you got some other digital audio source to check this problem yet.
DVD player?
--
Adrian C
Arfa Daily
"William Sommerwerck" <grizzle...@comcast.net> wrote in message
news:h9ydnVng3OevEuXV...@comcast.com...
> The Lady from Philadelphia sez...
>
> Why are you arguing about such an unlikely event when the OP hasn't tested
> the unit with another digital source?
>
>
Why ! - that's what makes life interesting, of course ... :-)
Arfa
Chronic Philharmonic
"Kendra Weissbein" <kweis...@lvhcc.com> wrote in message
news:g58uca$pb4$1...@aioe.org...
The sending device might be coding the datastream as a mono feed, or the
receiving device is failing to decode the datastream as a stereo feed. It
might be something as simple as a configuration problem (one of the devices
is set to 'mono'). To diagnose a fault, use a protocol analyzer, or a
process of elimination by substituting components until you get something
that works.
William Sommerwerck
There is no such thing, in consumer products, as a mono SPDIF feed. Indeed,
one of the design errors of the Compact Disc is the failure to include a
mono mode that would double disk capacity for pre-stereo recordings.
> or the receiving device is failing to decode the datastream as a stereo
feed.
Which makes no sense, as it's hard-wired to divvy up the signal into left
and right.
Richard Crowley
My money is on the receiver signal path beyond the decoder.
There are lots of places for just one channel to get lost.
William Sommerwerck
> There are lots of places for just one channel to get lost.
Which is what's happening. It just isn't happening in the original digital
stream.
Arny Krueger
news:yE_dk.146468$ft1.1...@newsfe14.ams2
> Unlikely or not, there is the remote possibility that
> this could be the one for that fault ... I don't know if
> the PCM data stream coming off the disc is decoded and
> processed first,
The data comes off the CD disc with the data interleaved. Physical data
blocks are 2352 bytes each, of which 2048 bytes are audio data. The 2048
bytes make up 1024 16 bit samples, 512 for each channel. The remaining data
is for error checking and correction.
> or whether it is directly transcoded
> into SPdif (or indeed, whether SPdif is just PCM under
> another name - I've never bothered to check because it's
> very rare to get *any* fault in this area). If there is
> any decoding going on, then just maybe, a channel *could*
> be lost.
Most consumer audio gear and a lot of professional gear use DAC chips with
either 2 channels or pairs of channels. In either case the input data stream
for each pair of DACs have the data for the 2 channels interleaved.
Arny Krueger
message news:48789E8D...@hotmail.com
> Gareth Magennis wrote:
>
>> "Mike S" <nospam> wrote
>>>
>>>> The problem is a fault in the sending device, or the
>>>> receiving device.
>>>>
>>> That narrows down the possibilities! At least he knows
>>> it's not the cable (obviously)
>>
>> Could someone please explain how it could be possible to
>> lose one channel of the digital stream out of the CD
>> player, considering that the CD's audio output is
>> perfectly OK.
Seems completely impossible, because the data for the 2 channels are always
interleaved. Each physical data block is composed of 1024 audio samples, 512
for each channel, and a separate block of data for error detection and
correction. Typically, the channel data is never de-interleaved.
> Failure to sync to the second block of audio data ? Bad
> clocks ?
Either situation will result in no audio data being recovered, just noise.
Gareth Magennis
"Arny Krueger" <ar...@hotpop.com> wrote in message
news:LZOdnSVCpeKbHOfV...@comcast.com...
Phew, after all that speculation we finally got some technical insight.
Thanks.
Richard Crowley
> Phew, after all that speculation we finally got some technical insight.
Didn't realize anyone was suffering from the delusion of any other cause.
Arfa Daily
"Chronic Philharmonic" <karl.u...@verizon.net> wrote in message
news:PDrek.137$6O4.0@trnddc06...
Even if it were, that would not result in the loss of one physical channel's
reproduction from the amp. What you would have is both left and right
channels combined into one single mono channel, which would then be
identically coded onto both left and right channels, within the single
SP/dif data stream. So you would get two channels physically reproduced, but
each containing the same mono audio.
Arfa
Richard Crowley
> "Chronic Philharmonic" wrote ...
>> The sending device might be coding the datastream as a mono feed, or the
>> receiving device is failing to decode the datastream as a stereo feed. It
>> might be something as simple as a configuration problem (one of the
>> devices is set to 'mono'). To diagnose a fault, use a protocol analyzer,
>> or a process of elimination by substituting components until you get
>> something that works.
>
> Even if it were, that would not result in the loss of one physical
> channel's reproduction from the amp. What you would have is both left and
> right channels combined into one single mono channel, which would then be
> identically coded onto both left and right channels, within the single
> SP/dif data stream. So you would get two channels physically reproduced,
> but each containing the same mono audio.
But only a fantasy academic discussion as there is no monaural mode
defined for SPDIF.
Arny Krueger
Agreed.
Since most home audio gear has DACs that are either 2-channel, or a number
of channel pairs, it is highly probable that *any* signal in the digital
domain has both channels present.
An exception would be something like a DSP that is running code to implement
a balance control or channel level control.
Chronic Philharmonic
"William Sommerwerck" <grizzle...@comcast.net> wrote in message
news:_7ednRdYQaCszefV...@comcast.com...
>> The sending device might be coding the datastream as a mono feed...
>
> There is no such thing, in consumer products, as a mono SPDIF feed.
> Indeed,
> one of the design errors of the Compact Disc is the failure to include a
> mono mode that would double disk capacity for pre-stereo recordings.
Right, I was thinking AES3.
>> or the receiving device is failing to decode the datastream as a stereo
> feed.
>
> Which makes no sense, as it's hard-wired to divvy up the signal into left
> and right.
Right, I was thinking AES3.
Arfa Daily
"Richard Crowley" <rcro...@xp7rt.net> wrote in message
news:_rqdnZGFkdqcEufV...@posted.pcez...
Probably true enough, but the occasional flight into academic fantasy does
no harm, and keeps the old grey cells firing ... d;~}
Arfa
EADGBE
OK, I remembered that one of my other CD players--a Magnavox CDB650--
also has a digital output.
I patched it into the Yamaha preamp and got the same results--no right
channel sound.
I also tried another cable (dumb, I know--I'm still thinking
"analog"!) and got the same results.
I also tried using another one of the preamp's digital inputs and got
the same results.
So I can safely say that the fault lies somewhere inside the preamp.
Time to get out the hammer and duct tape......
Gareth Magennis
"EADGBE" <hwbos...@comcast.net> wrote in message
news:b187f3aa-2038-40ff...@25g2000hsx.googlegroups.com...
Far be it from me to say I told you so, so I won't.
Actually your original instincts were right. Digital either works or it
doesn't.
Gareth.
Gareth Magennis
As for the cause of the problem in tha pre-amp, one can only speculate even
more, we know how much fun that is. If you have a scope you can just follow
the signals from the D/A converter output onwards until one dissapears.
Could be anything at all really. It might be worth tapping and banging
things to see if it's a mechanical intermittent, other than that it's just
plain fault tracing. Could just be a selector switch. But I'm just
speculating again aren't I. Tch.
Gareth.
Don Pearce
Ah, you don't have a DAB radio then? The background sound of boiling mud
in low signal conditions is a joy.
d
Arfa Daily
"Don Pearce" <nos...@nospam.com> wrote in message
news:LuydnbbIeOKpDOHV...@posted.plusnet...
LOL !!
Arfa
Richard Crowley
> Gareth Magennis wrote:
>> Actually your original instincts were right. Digital either works or it
>> doesn't.
>
> in low signal conditions is a joy.
But that IS "working" according to the people who specified
and designed the system. The low-level hash was determined to
be an acceptable tradeoff in the overall scheme. (Compare the
performance of MP3, etc.)
EADGBE
wrote:
>
> Far be it from me to say I told you so, so I won't.
>
> Actually your original instincts were right. Digital either works or it
> doesn't.
>
> Gareth.
Gareth:
Oh, I never doubted your assessment.
I just wanted to do some more testing, in the interests of thoroughly
defining the problem.
I suspect that the problem is physical (broken solder connection,
etc.) rather than electronic...at least I hope this is the case.
It will be some time before I have time to sit down and see what the
problem is, but when I do, I will let everyone know what I find.
Many, many thanks for all of the kind assistance!
Arfa Daily
On Jul 14, 7:12 pm, "Gareth Magennis" <gareth.magen...@ntlworld.com>
wrote:
>
> Far be it from me to say I told you so, so I won't.
>
> Actually your original instincts were right. Digital either works or it
> doesn't.
>
> Gareth.
>Gareth:
>Oh, I never doubted your assessment.
<snip>
In reality, none of us did really. We wuz jus' messin' wiv ya and adding a
bit of interesting debate to the issue ... d;~}
Arfa
Don Pearce
I don't mean that, I mean this - what happens when there isn't enough
signal strength.
http://81.174.169.10/odds/baddab.mp3
d
Gareth Magennis
That sounds like John Humphrys pretending to be a Dalek.
I think its slightly less annoying than FM radio on the edge of reception,
where it would sound like he was pretending to be a force 9 gale in mono.
Gareth.
Don Pearce
Yes, but there is an important difference - the FM signal drops into
noise gracefully and slowly. That DAB signal is only 1dB or so bigger
than one that is not received at all, and 1dB bigger again would be
received cleanly.
d
Arfa Daily
I think that when push comes to shove, a lot of the 'digital revolution',
including DAB, is about money, not any advantage to the consumer. DTTV
clearly shows this where, despite the limited bandwidth available for
transmissions, government and the regulators, continue to sell licences to
every little tinpot Tom Dick and Harry station, which then get crammed into
yet another multiplex, until there's no longer enough space left there for
everyone to get in a decent bitrate, whereupon it's discretely downed, and
stations start to get on the edge of Dalekism. Likewise, TV stations start
to have objectionable motion artifacts to the point of area blocking on some
of the worst affected ones.
That's not to say that digital transmissions *can't* be good in terms of
viewability and listenability. A 'good' full bitrate DAB transmission, or
better yet a radio or full bitrate satellite channel, can be excellent and
at least up to, if not exceeding a comparable analogue transmission of full
quality. It's just a shame that no matter how good the starting point, a
coupla dB is the difference between reception and digital cliff. Personally,
I'm with Don on that one, and I'd rather see the picture or hear the sound,
gradually deteriorate, as the signal level falls off.
So, is Freesat going to knock Freeview on the head ? I can't see any reason
why not, and can see one very good reason why it might.
HD
And that brings us back to the bandwidth issue ...
Arfa
Richard Crowley
> Yes, but there is an important difference - the FM signal drops into noise
> gracefully and slowly. That DAB signal is only 1dB or so bigger than one
> that is not received at all, and 1dB bigger again would be received
> cleanly.
That is a general problem with ALL digital communication,
it has a much different degradation behavior.
Don Pearce
Yes, but too many system calculate their link budgets very marginally. A
two-way mobile broadband system I'm currently deploying gets round this
by using remote transmitter power control; the receiver tells the
distant transmitter how much power to send so it stays just the clear
side of threshold. It's amazing how little interference you cause that way.
d